This medical ninjutsu allows the user to speed up the body's natural healing process by sending chakra from their hands into a wound or afflicted body part. This allows the user to heal a patient without the need for medical equipment or surgery, making it highly useful on the battlefield. It can be used to treat both external and internal injuries. It is vital to match the amount of chakra used to the severity of the affliction or injury. This requires a great amount of chakra control. Because of this, only a few highly skilled medical-nin are able to use this technique. Kabuto demonstrated the ability to use it a short distance away from the target instead of through direct contact.[2]

By sending an excess amount of chakra into the patient's body, the user can overload the patient's normal circulation, trapping them in a comatose state.[3] Although this is usually undesirable, Kabuto once effectively used this side effect to get Kiba Inuzuka out of his way.

In Konoha, medical-nin seem to learn this technique by practising with fish.[4]

Trivia

Although the last part of this technique's name is written the same as senjutsu, it doesn't refer to the same thing. Senjutsu refers to the techniques used by the toad and snakesages while this technique's name refers to the secret of immortality the legendary real-life sages allegedly had.